SPring-8, the large synchrotron radiation facility

Date : 15:00-16:30 December 15, 2008

Speaker : Tsutomu Matsui

Affiliate : The Scripps Research Institute

Title :
Time-resolved electron cryo-microscopy revealed maturation dynamics of a pseudo T=4 viral capsid

Abstract :
Nudaurelia Capensis omega Virus (NωV) is a member of Tetravirus, T=4 non-enveloped icosahedral ssRNA viruses. The virus like particles (VLPs) of NωV coat protein were expressed and purified at neutral pH as procapsid particles (Diameter = 480 Å).  Procapsids transit to capsids (420 Å) with auto-proteolysis when the pH is lowered to < 5.2.
In present studies, the wild-type VLPs were immediately frozen at different time points after lowering pH from 7.6 to 5.0. Electron cryo-microscopy and single-particle reconstruction techniques were than used to solve the particle structures at the various time points. Difference density maps were computed and were interpreted with the crystal structure and biological data. The results reveal the sequence in which cleavage site formation occurs and illustrates the process of pseudo T=4 icosahedron formation in NωV.

Organizer : KUMASAKA (PHS : 3475)